Thermal derating and enclosure integration
The 250 A rating holds flat from 40 °C through 50 °C, then derates to 241 A at 55 °C and 213 A at 70 °C. In a sealed panel with limited airflow, the 70 °C ceiling means the breaker must be loaded to 213 A or less to stay within the thermal curve. Power dissipation peaks at 50.5 W — account for that heat in the enclosure's thermal budget.
Trip unit and auxiliary configuration
The ETU320 electronic trip unit provides LI (long-time and instantaneous) protection with adjustable settings. The breaker includes a mechanical trip indicator for visual fault confirmation. No communication function, phase failure detection, or ground fault monitoring is fitted on this variant.